Automatic magnetic circuit-breaker.



Patented Aug. 9,1910e 2 SHBETS-SEEET 1.

W. M. SCOTT. AUTOMATIC MAGNETIC CIRCUIT BREAKBB..

APPLIGATION FILM) JUNE a, 1901` W. M. SCOTT.

AUTOMATIC MAGNETIC CIRCUIT BRBAKER.

APPLIOATION FILED JUNBB, 1901.

966,708. Patented Aug.9,191o.

2 SHEETS-SHEET 2.

,A M EI se- W/TNESSES /N VEA/70H. l

Il Il',

A TTOHNEY rus Naam: msnm: co., WASHINGTON, n. c.

UNITED STATES PATENT OFFICEG WILLIAM M. SCOTT, CF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO CUTTER ELEC- TRICAL S5 MANUFACTURING COMPANY, A OORIBORATION 0F NEW JERSEY.

AUTOMATIC MAGNETIC CIRCUIT-BEE.A.KER.

'lo all whom fit may concern:

Be it known that I, limitan M. Sco'rfr, a citizen ot the United States, residing at Philadelphia, in the county ot Philadelphia and State oit Pennsylvania, have invented a new and useful Automatic Magnetic Circuit-Breaker, of which the following is a specification.

My inventionrelates to automat-ic switches and more especially automat-ic magnetic circuit breakers, whose purpose is to control or interrupt a. circuit upon the occurrence of predetermined electrical conditions.

It is the object olf my invention to provide automatic electrical apparatus which shall control or interrupt| a circuit carrying large lighting or power currents of either low or high potential, the structure ot the apparatus being such that it is impossible to move the switch or circuit breaker to normal or closed position and. retain it .in such position during the continuance or existence ot predetermined electrical conditions. By the structure hereinafter described it impossible for an operator to reset a circuit breaker or to wiltully hold the same in normal oi circuit closing position if abnormal circuit conditions exist or continue. The apparatus may be styled a non-closable circuit breaker.

My invention resides in other features hereinafter described and pointed out in the claims.

For an illustration of one of the forms my invention may take, reference is to be had to t-he accompanying drawings, in which:

Figure 1 a side elevation ot a circuit breaker embodying my invention. and showing the same in normal or circuit closing` position. Fig. 2 is a view similar to that o't Fig. l showing the parts in open position, part of the framework being broken away to more clearly illustrate more essential parts. Fig. 8 is a. trent elevation ot the circuit breaker when in circuit. closing position. Fig. 4 is a vertical sectional view oit the laminated bridging member, such view being taken on the line l-t oit Fig. Fig. 5 is a plan view of a toggle link litted with adjusting means. Fig. 6 is a horizontal sectional view taken on the line 6-G ot F Referring to Fig. 1, 1 is a siiun'iortiiig member o arm having a pivot 2 about which Specification of Letters Yatent.

Application led June 8, 1901.

Patented Aug. 9, 1910.

Serial No. 63,690.

it may rotate in the housing or bracket 38 secured upon the base B oit slate, marble, or other suitable insulating material. The laminated bridging member 3, built up of a plurality of sheets or plates of copper or other suitable conducting material, is secured to and insulated from the arm or supporting member 1. The metallic supplementary or shunt contact l is resiliently supported by and insulated from the arm 1. The movable carboi'i shunt Contact is also carried by and insulated from the member 1 and is rotatable under spring control upon the pivot 5. The main terminals or contact blocks 6 and 7 are secured upon base B and have their' engagino' or contact races in practically the same vertical plane and are adapted to be engaged thereon by the ends of the laminas constituting the bridging member 3. A metallic shunt Contact 8, cooperating' with contact et, is secured upon and in electrical communication with the upper terminal block (5. Secured upon and in electrical communication with the contact G is a bracket on which the stationary shunt carbon 9 is rotatable under spring control upon the pivot 9.

An actuator or operating lever 10 is pivoted upon the bracket 38 at 10. A toggle link 11 is also pivoted at 10 and is rotatable or movable independently of the actuator 10. The link 11 is pivoted at 12 to the second toggle link 18, which latter is pivoted at 14 to the supporting member or arm 1. The latch 15 is carried by the actuator 10 and pivoted thereto at 15. 15a .is a web in the actuator 10 which serves as a stop for limiting the clock-wise rotation of the latch 15 about its pivot 15 as viewed in Figs. 1 and 2. Approximate the outer end ot' the toggle link 11 is pivoted the roller 1o which is adapted to be engaged or embraced by the hook o1 the latch The second latch. 17 is pivoted at 18 to the bracket 38, the spring 27', attached at its one end to the bracket 8S and at its other end to the latch 17, serving to exert an upward pull upon the latch 17 The hook of the latch 17 is adapted to engage roller pivoted independently of the latch 15 upon or concentric with the pivot 15. The lever 19 also is pivoted at 18 but independently o'l the latch 17. Its outer end 19 is adapted to engage upon the top of the tail 15b of the latch 15. The inner end of the lever 19 is adapted to be engaged upon its under side by the lever 20 pivoted to the housing 38 at 20. The core 21 of the solenoid winding 22 (consisting of turns of heavy copper conductor connected in series with the main contacts 6 and 7 and the bridging member 3, when the circuit breaker is designed to respond to an abnormal current flow) is provided with a head 21 which is adapted to engage the under side of the lever 20a mechanically connected to the lever 2O and rotatable therewith about the pivot 20. The screw 21"L serves to adjust the height of the core Q1 so that the apparatus may be set to respond to different current values.

llVith the parts in open circuit position as shown in Fig. 2, if it is desired to close the circuit breaker, the operator grasps the actuator or operating lever 10 by the handle 10a and raises it until the hook of the latch 15. under the influence of either gravity or a spring, engages the roller 1G thereby locking the actuator to the toggle link 11, or in effect to the movable contact member. By then depressing the actuator 10 the toggle links 11 and 13 straighten out and come more nearly into the same straight line until the parts reach the position shown in Fig. 1. At this stage the pivot 12 falls slightly short of the imaginary straight line joining the pivots 14 and 10. lVhen this position is reached the hook of the latch 17 engages the roller pivoted at 15 upon the actuator 10, thus locking the mechanism in circuit closing position. The locking strain is therefore transmitted in succession through both the connecting latch 15 and the second latch 17. Thus the connecting latch 15 intervenes between the second latch 17 and the movable contact member, and it is through the medium of the two latches in series or tandem, as it were, that the locking strain is transmitted. lllhen the parts are in circuitclosing position the springs and 24- are under tension, the spring Q11 intervening between the supporting member or arm 1 and the housing 3S, and the spring 23 between the housing 38 and the toggle link 11.

In order to secure the desired pressure of the laminated bridging member 3 against the terminal blocks G and 7, the link 13 has an adjustable connection with one or the other of the members 1 and 11. This adjusting means consists, as shown in Figs. and G, of an eccentric bushing 98 slightly tapered exteriorly and fitting in a correspondingly tapered hole in one end of the link 18. The eccentric bushing Q8 has a flange upon its one end while its other end is threaded to receive the nut 29. The axis of the hole 31 through the bushing Q8 is eccentric with respect to the circumference of the bushing so that the distance between the centers of the holes 30 and 31 in the link 13 may be CUL), UU

changed or varied by rotating the bushing 28 with respect to the link 13. The taper of the circumference of the bushing 28 and the corresponding taper in the opening or hole 1n link 13 serves, when the nut Q9 is drawn up, to lock the bushing securely in the desired position.

rlhe curvature or shape of the laminated bridging member 3 is maintained and determined principallyT by the rigid yokes 3Q and 33 between which it is clamped by the bolts 33, 33 being secured to or integral with the member 1. Adjustment of the curvature or shape is effected by the screws 3l threaded through the member 33 and pressing upon the steel plate to cause a flattening out or closing up of the bridging member 3 according to the position of the screws Slt. The metal strip 3G is carried between the steel plate 35 and the bridging member 3, is insulated from them and carries the resiliently supported metallic shunt contactI et. The strip 3G is maintained in permanent electrical communication with the lower main terminal 7 by means of the flexible conducting cord 37.

The operation is as follows: Assuming the parts in circuit closing posit-ion as shown in Fig. l, if the current rises in value and attains or exceeds the value for which the solenoid core 21 has been set, that core is drawn forcibly upward by the magnetic effeet of the current through the winding Q2 and delivers a blow to the under side of the lever Q0 thus forcibly rotating the lever 20 in a counter-clockwise direction, as viewed in Figs. 1 and 2, and delivering a blow, through the medium of the lever 1f), upon the top of the tail 15" of the latch 15. The result is that the latch 15 releases the link or member ll, permitting the movable contact member, under the influence of gravity. the tension of the springs Q1 and and the blow delivered to the roller 1G by the cam surface 15,C of the latch 15, to fly to open position. At the beginning of the opening' movement, the laminated bridging member separates from the main contacts 6 and 7, thus shunt-ing the current through the supplementary shunt contacts s, S and 5, 9. Later, the metallic shunt contact -l separates from the contact S, and finally the carbon 5 separates from the carbon 9 causing the final break of the circuit and the arc to occur between said carbons, and relieving the metallic portions of the switch from detrimental effects of arcing, such as pitting or fusing. During the opening movement, the actuator 10 remains locked to the bracket 3S by the latch 17. As the opening movement approaches its end, the projection or stud 25, secured upon the under side of the toggle link 11, strikes upon the top of the latch 17 and rotates it in a clockwise direction about its pivot 18, as viewed in Figs.

l and 2, releasing the actuator 10 so that it .may be again lifted, heretofore described, to permit the latch l5 to lock it to the link 11. Suppose, however', that the condition of the circuit causing the abnormal flow of current in response to which the circuit breaker was tripped, to still continue. If the operator raises the actuator' l() and couples it to the link l1., and then depresses the actuator l0 in the act of closing the switch, at the initial closure of the circuit and before the latch 17 engages and locks the actuator l0, the abnormal current will again instantly iiow causing the core 21 to be again attracted and to deliver a blow through the levers '20, 20, and 19 to the latch 15, disconnect-ing the link ll from the actuator l0 and permitting the circuit breaker to iy open while the operator still holds the actuator l0 grasped in his hand. That is to say, the circuit breaker is a nonclosable one in the sense that the operator is robbed of control during the existence or continuance of abnormal circuit conditions.

IVhile I have herein shown a circuit breaker operative upon excessive flow of current, it is obvious to those skilled in the art, that the latch l5 may be operated or controlled by any other suitable electro-responsive means.

that I claim is:

l. In an electric switch the combination of fixed and movable contacts, spring means for causing the` opening of the switch, a manually operative member' for closing the switch, an intermediate member for disengageably maintaining operative relationship between the manually oper'ative member and the movable contact, a latch adapted normally tomaintain engagement between the manually operative member and the intermediate member, a second latch adapted normally to maintain the manually operative member in the closed position, automatic magnetic means adapted to cause the operation of the first latch to release the intermediate member upon a predetermined flow of current, means controlled by the intermediate member to actuate the second latch to release the manually operative member after the release of the intermediate member, substantially as described.

2. In an electrical switch, a movable contact member, an operating member therefor', an actuator, a latch for locking said actuator and said operating member together, a second latch adapted to engage said actuator, electro-responsive means for unlocking said actuator from said operating member, and means operative after said movable contact member has moved to abnormal position for actuating said second latch to release said actuator.

3. In an electrical switch, a base, a movable contact member, an ope 'ating member for said movable contact member', an actuator, a latch for locking said actuator and said operating member' together, a latch for locking said actuator to said base, means for unlocking' said actuator' from said operating member on attempted movement of said contact member' to normal position during the existence or continuance of abnormal electrical conditions, and means operative after said contact member has begun to move to abnormal lposition for unlocking` said. actuator from said base.

l. In an electrical switch, a base, a movable contact member, an operating member for said movable contactmember, an actuator', a latch for locking said actuator and said operating member together, a second latch for locking said actuator to said base, means for unlocking said actuator from said operating member on attempted movement of said contact member to normal. position during the existence or continuance of abnormal electrical conditions, and means moving with said contact member for engaging said second latch to unlock said actuator from said base.

5. In an electrical switch, a base, a movable contact member', an operating member' for said movable contact member, an actuator', a latch for locking said actuator and said operating member together, a second latch for locking said actuator to said base, and means for unlocking said actuator from said operating member on attempted movement of said contact member to normal position during the existence or continuance of abnormal electrical conditions, said operating member engaging said second latch upon movement of said contact member to abnormal. position. to unlock said actuator from said base.

G. In an electrical switch, a base, a movable contact member, an actuator therefor, means for connecting said actuator with said contact member', and means for locking said actuator to said base, means responding to predetermined electrical conditions for breaking the connection between said actuator and contact member, and means for thereafter unlocking said actuator from said base.

7. In an electrical switch, a base, a movable contact member, an actuator, a latch for locking said actuator and movable contact member together, a latch for locking said actuator to said base, electro-responsive means for unlocking said actuator from said contact member, and means associated with said contact member for unlocking said actuator from said base.

8. In an electrical switch, a base, a movable contact member, an actuator, a latch for locking said actuator to said contact member, a latch for locking said actuator to said base, electro-responsive means for unlocking said ILO contact member from said actuator, and automatic means for thereafter unlocking` said. actuator from said base.

9. In an electrical switch, a base, a movable contact member, an actuator therefor, a latch tor locking said actuator to said contact member, a latch for locking said actuator to said base, electro-responsive means for unlocking said actuator from said contact member, said actuator being unlocked from said base by the movement of said contact member after it has been unlocked from said actuator.

l0. In an electrical sivitch, a base, a movable contact member, an independent actuator therefor, means for locking said actuator to said base, said actuator being unlocked from said base by the movement of said contact member independent ot said actuator.

ll. In an electrical sivitch, a base, a movable contact member, an actuator, means for locking said actuator to said base, and electro-responsive means for causing movement ot said contact member independent otl said actuator, said actuator being unlocked from said base by the movement of said contact member independent of said actuator.

l2. In an electrical switch, a base, a movable contact member, a toggle for operating said contact member, an actuator, means for locking said actuator to said base, and electro-responsive means for causing` movement of said contact member independent of said actuator, said actuator being unlocked :trom said base by the movement of said contact member independent of said actuator.

12?. In an electrical switch, a base, a mov- OUV, l uu able contact member, an actuator, latches for locking said actuator and contact member together and for locking the sivitch in normal position, electro-responsive means for unlocking the actuator from the contact member, the actuator being unlocked by said contact member after the same is moved to open position.

14C. In an electrical switch, the combination With a base, of a movable contact member, an actuator, a latch for locking said actuator and contact member together, a latch for locking said actuator to said base, whereby the switch locking strain is transmitted through both latches in succession, said actuator being unlocked from said base upon the movement of said contact member to open position.

l5. In an electrical switch, the combination With a base, oit a movable contact member, an actuator, a latch pivoted to said actuator for connecting the same to said contact member, and a latch for locking said actuator to said base and engaging at the pivot of said iirst named latch.

16. In an electrical switch, the combination with a base, of a movable contact member, atogglev for operating the same, an actuator, a latch for directly connecting said actuator to a link member of said toggle, a second latch for locking said actuator to said base, and electro-responsive means for disconnecting said actuator from said toggle link member.

IVM. M. SCOTT. Witnesses MAE HOFFMANN, EUGENE Zmomnz. 

